If you're using one of the 10 Horizon themes (Tinker, Ritual, Fabric, Pitch, Dwell, Savor, Horizon, Heritage, Atelier, Vessel), you can easily use app block to add the Star Rating Badge on your collection pages.
Considerations
Google doesn't accept review snippets for the homepage, Reviews Page, and collection page as they should only “provide review information about a specific item, not about a category or a list of items".
Install Star Rating Badge on collection pages
Step 1: Enable Judge.me app embed
To enable Judge.me app embed:
From your Shopify admin, go to Online Store > Themes.
Find the theme you want to edit and click Edit theme.
From the menu on the left, click the App embeds icon (the third icon).
Enable the Judge.me app embed.
Click Save on the top right.
Step 2: Add the Star Rating Badge code
For the Star Rating Badge to show on your collection pages:
From your Shopify admin, go to Online Store > Themes.
Find the theme you want to edit and click Edit theme.
At the top of the theme editor, open the template dropdown in the middle.
Select Collections, then select Default collection.
On the left panel, inside Template, find the Collection section.
Click the right-arrow icon (>) on its left to expand it.
Hover under the Price block and click the plus icon (+).
Open the Apps tab.
Select the Star Ratings block.
(Optional) Hover over the block, hold the 6-dot icon (⋮⋮), and drag it up or down to change its position.
Click Save on the top right.